我是mathematica的新手,我遇到了这个标志,有人能告诉我这意味着什么吗? =!=
If[m - l =!= 0, net0 = convtomat[dd,m - l];
row0 = {}; row1 = {}; row2 = {};
Do[
row1 = Append[row1, net0[[1, j + 1]]], {j, 0, m - l}
];
ccts = Join[ccts, row1],
ccts = Join[ccts, dd]
]